Opioids to all you pepole who say fentanyl has no legs, please explain this to me

[kleinerkiffer]

http://www.ncbi.nlm.nih.gov/pubmed/18728103

RESULTS:

The pharmacokinetics of intravenous fentanyl reflected a 2-compartment model with a clearance of approximately 1.5 L/min. There was moderate (<50 %) between-subject variability (BSV; %CV [coefficient of variation]) in the systemic kinetics of fentanyl. Bioavailability of intranasal fentanyl was 89%, following first-order absorption, with a lag of approximately 5 minutes and a half-life of approximately 6.5 minutes. Interpatient absorption variability was approximately 30% BSV for all absorption parameters. Intranasal versus intravenous administration led to a delayed mean fentanyl time to maximum concentration (13 vs 6 min) and lower maximum concentration (1.2 vs 2.0 ng/mL). Analgesic effect lagged behind the venous fentanyl concentration, with a half-life of approximately 2.5 minutes as described by a fractional sigmoid maximum drug effect dynamic model. The concentration-analgesia relationship was steep, with a 50% effective concentration of 0.46 ng/mL (Hill coefficient 3.5). Intranasal onset and offset of analgesia were slightly delayed, principally due to the delay and lag in systemic absorption, with slightly lower peak analgesic effect, compared with intravenous fentanyl. Duration of effect was directly related to intranasal fentanyl dose, with pain scores returning to predose values at approximately 120 minutes (75 microg) to approximately 240 minutes (200 microg) after a single dose.

That's really odd

 

[SS373dOH]

^ The scary part is, now they have to find out all the pharm data for all fentanyl's analouges! It's going to be a crazy mess of different conflicting data!

I wish there was a clear database that had all half lifes, onsets, duration of actions, bioavailabilities, ect. for all of these fentanyl analouges. Other than the main 2 or 3 analouges, there just isn't enough information out there.

The lack of concise information leads to dangerous situations. And the fact that one analouge can have a far greater potency, and other differences, doesn't help.

 

[bingey]

The nasal is a mistake shoddy research happens all the time.


It should be between iv which is 60 min to 2 hours and sublingual which is around 7 hours . I'd say 3/4 hours I'd bet my life on it being that rather than 10 minutes

 

[Keif' Richards]

Legs = Slang for how long the perceived effects of a drug last. It is said that Fentanyl has "no legs" because compared to other Opioids like Morphine or Heroin, it is a very short-acting drug.